I know there are millions (hyperbole) of threads telling you how to make gold. My thread might have the exact same methods as everyone else, but hey, it'll be good!

Method 1: Nurturing
Some people may not even consider this as a method. I do! Here's how it works...
I know this sounds like overkill and a complete waste of time but it's NOT. Nurture at LEAST 750 Sylesti per day. Egglings are the easiest since they only have 4 options, but Hatchlings are quicker because a row will usually have the same needs. Anyway, nurture 750 per day. Sure, not everyone has the time for this, but it's also a good way to get people to know you and your pets. Here's the order in which I will nurture...
- My Own Pets
- Users who Nurtured my Pets Today
- Pets that Me And My Friends Own
- Users Who Are Online
- All Pets
That way, you can speed up your own pets and give back to the people who have nurtured your pets! Also, every Sylesti you nurture gives you a scale These can be spent at the scale shop. You can get great eggs and rewards for this and is useful for projects as you can get Dyes. Also, if you have pets up for sale, people may nurture those pets and then say 'Hey, that's the pet I want!'. Then they buy it, and you get money.

Method 2: Battling and Missions
Here's another method. Battling. In this method, you simply battle! Re-doing battles is okay too. When you get enough relics and armor and accessories, go over to your inventory. You can either use the Trade Broker or just sell them. DO NOT SELL THEM AT THEIR BASE PRICE WHEN SELLING AT THE BROKER! This is very important, as there is a small tax fee when you sell them. You could've just sold them in the inventory. Anyway, if you sell them in your inventory, there are 2 ways to do this. Either right click on the item and it will immediately go to the sell area OR click the item and then click an empty box in the selling area.
Then there is the missions part. This one is VERY common. Here's what I did.
First, I found some cheap pets on Advanced Search. Then I attuned them to an element. I had 10 pets that I used and so I did 2 pets per boost. Them I just had them do missions! Also, if you save up all your satchels and open them all at once then you get a larger sense of achievement.

I will add more to this whenever I can! I hope this helped!

eggs and hatchlings have the same chance of giving items.